The present invention relates to an Ni--Cr--W--Al--Ti--Ta alloy exhibiting an excellent heat resistance, a high creep rupture strength and an exceptional good corrosion resistance with good forgeability. Therefore, the alloy of the present invention can be utilized as a material for parts of power generators or various types of equipment exposed to chemicals which are required to be operated at a high temperature, e.g. over 1000.degree. C., under a highly corrosive atmosphere.
In order to improve heat efficiency, there is a tendency when operating many types of equipment to use a temperature that is increased, to say, over 1000.degree. C. To meet the afore-mentioned conditions, an alloy which exhibits excellent high temperature characteristics is desired.
Here-to-fore, concerning conventional heat-resistant alloys, a series of cast precipitation hardened nickel-base superalloys have been considered to be suitable with regard to high temperature strength properties. However, these alloys are poor with regard to forgeability properties in combination with formability properties. Many other inventors alloys have been developed which exhibit a good workability without the deterioration of other mechanical properties. For example, such alloys that have been disclosed include 23%Cr-18%W-Ni alloy disclosed in Japanese patent publication No. 54-33,212 and Ni--Cr--W alloy disclosed in United Kingdom patent No. GB 2103243A. According to the above-mentioned references, the alloys are composed of by weight less than 0.1% of C, 21 to 26% of Cr, 16 to 21% of W, less than 1% of Ti, less than 1% of Nb, less than 0.1% of B, less than 0.5% of Zr, less than 1.0% of Hf, less than 1.5% of Al, less than 6% of Co, less than 3% of Mo, less than 6% of Fe, and the remainer of the composition being Ni. The present invention relates to an alloy exhibiting a high workability as a well as high temperature strength at above 1000.degree. C. The alloy which is disclosed in Korean Pat. No. 16420/ has a composition of 16.5% Cr-21.5%W-1.5%Al-0.9%Ti-BalNi.